Process of forming a closure on a collapsible tube



1 Sept. 1, 1936.

c. J. WESTIN PROCESS OF FORMING A CLOSURE ON A COLLAPSIBLE TUBE Filed June 21, 1933 W/IWE'SS:

2 Sheets-.Sh eei -1 PVC-7.2.

1 PROCESS OF FORMING A CLOSURE ON A CQLLAPSIBLE TUBE c. J. WESTIN Filed June 21, 1935 2 Sheets-Sheet Patented Sept. 1, 1936 UNITED STATES PATENT OFFICE PROCESS OF FORMING A-CLOSURE ON A COLLAPSIBLE TUBE Charles J. Westin, Philadelphia, Pa., assignor to F. .LStokes Machine Company, Philadelphia, Pa., a corporation of Pennsylvania Application June 21, 1933, Serial No. 676,912

2 Claims.

be closed which portions arezformedi by the spreading or bending of Ethe walls of .the tube during;the:- closing or: folding operation: at (that end.- Thesezportions canconveniently consist of curved or arcuate" steps .or arches in the :wallsof the tube.

The tubesj which: form. the subject matter of this application may conveniently bemade in the tube cups which areillustratedi and described in my'co-opending application for Letters Patent on a Tube closingv machine, filed June 2l, 1933,

Serial No.'676,9l1.'

Another purpose of my invention, is .to :produce a-zclosed 'tube:.-which;=will; (hold a -volume of; 'the maximum; amount of material possible for a given size of-tube; is ,awomplished by keeping-the circular: section of the itubepractically constant all therway; to theend'of the tube, allowingonly aryery'short portion of taper in order to get .the necessary length of flat .part of theltubepwalls at ,1 thezend' to qformxthe required number; of r folds in closing it. Bygclosing tubesaccording to the new and cnoyel process, here-described, a tube is produced, which-will hold ten tofifteen percent. more material thana tube CIOSBdgiH? theold way. In other words,-;the;present:standard-tube used to hold: a certain amount-ofi-material can be 3/ inch to /2 '1 ineh -shortenand still' provide; ample room for the psameivolumezof material.ifclosed by the new 40methoda (This, means,- a" considerable saving; taking .foreexample witha one inch tube being :filled atth'e rateof; forty per minute, eight hours aday, or one; hundred and {thirty gross penday, the saving -would amount to .'$11.83'-a .day ifa ,3 inchgshorter tubewaspsed and with tin .at 35 a .poun d; The savinggorr the continuousproduction of -o ne ;.year, countingqtwmhundredt anctfifty Joperatingz days, would amountgto $2,957 .50. The "Sa ingis-of ;course;. in. proportion-atothe size of .tube ;usede--It should alsoibe noted. that-"this saving is'ionlyf: fi'guredzon: the metal .used in the tube fandfiat the ;.present.low:market price ofitin. Qtheritems. of course, also enterinto thesaving *such as; the:.use;.ofsmallerxcartons and.packing 'fected byv the. stifiness of the content. This spreading.anddiattening of the tube body de- Heretofore, it has been the practice to place the tubestinto short holders or tube-cups, which hold. thetubesat the capped end .2 while they are beingtconveyed fromone station to'another in the filling and closing machine. Standard 5 practice has been to make the recessof the tubecup,.into which the tube is'iplaced, about the same'depthas the diameter .of the tube. Tubes held in .these cupswill, whenibeing flattened at the open end toprovide the necessary flat por- 10 tion required .for. the.closing folds,.spread out sidewise, changing their shape gradually from a perfect cylinder at .thebreast or capped portion to the flat sectionat thefolds, .the'sides tapering out. from the breast to the. end of the folds while thefaceandback taper in from the breast to the folds. The rate at which a tube naturally spreads and flattens varies for'difierent materials used in vthextube'walls and. is also slightly afcreases the volume. It should be noted that the tube'must be held fairlyrigidin'the cup, so. asito prevent wobbling as .they' are conveyed from one mill out the tube-cup bell-shaped, allowing. only .1 35

about one-quarterof the depth from the bottom to remain straight, and relying on this short "straight portion to keep the tubes in a perpendicularposition. Without the taper or bell- :shape inlthecup, a8.referred to above, the tubes would have objectionable dents or wrinkles in i the .sidesatthe end .of the-straight part of the recessinxthe cups. It is evident that the straight portionninithe recess has to be a: fairly snug fit on thetube in order..to hold1the tubes .of any length up toten to twelve inches rigidly in a perpendicular position so as to avoidbad folds. On the other hand, it is, of course, impossible to maintain exactly the same diameter on a lot of tubes becauseof .the wearinthe dies, and because 50 of the varying. thickness of the enamel and lacqueriadded in lithographingthetubes, and it was therefore necessary'to allow a few thousandths of an inch clearance in the straight portion ofithetube-recess; so that the operator would be able topush the tube down against the shoulder or bottom of the recess. The close fit required in the tube-cup, and the varying diameters found in the 'manufacture of tubes has always caused considerable trouble to the operator in properly placing the tubes in the machines at the desired productiorr rate.

By my invention the above "difiiculties are entirely eliminated. The tube-cups are made in proportion to the length of the tube and support the tube close up to the fold. The tubes being" supported practically throughout-their entire length do not have to be held rigid in the cup as previously was necessary, but a clearance as diameter tube, this clearance being less for smaller tubes and larger for tubes of larger diameters.

In connection with this full length, nibectp; of my co-pending application, referred to above,

it is, however, necessary to. use what is known as apreformer, as shown in my co-pending application, in order .to get uniform results and =maintain a definite shape of the tube as it is being closed. 3

By this novel and new arrangement of holder and former, a definite shape can be given to the tube asitis' being closed,'and this shape remains uniform at all times regardless of the type of material used in the tube walls or the contents of the tubes. To get the maximum material into a tube the support or top of the tube-cup should come to about -}%'of .thediameter from the top so as to become of squarearea.

of thetube. This allows sufiicient distance for fiattening'the' tube for the required number of foldsand permits the tube to form into a pleasing Gothic arc in outline, when looking at the tube from'the side of the tube or end of the fold. To prevent unsightly wrinkles or dents in the tube walls below the folds as well as in the folds themselves, it is necessary to spread theopen end of the tube. As'the open end of the tube is spread out by the preformer the sides of thetube are held or supported by the top of the tube-cup and the break between the straight cylindrical "side'of the tube and the spread out iportion above the top of thetube-cup'forms itself into an arcuate fold' or step. This fold or step becomes more "pronounced as the tube is closed, but the change of shape 'in the tube, froma perfect cylinder into one havingflat face and back, is brought about sharply by having the top of the tube-cup of proper width and curvature, so thatthe arcuate step properly dies out in the cylindrical portion of the :tube without causing the tube to fiatten The angleat .which thesidesof the top of the tube-cup are cut away to leave acurved'top is'of noparticular importance as long as it is notinterfering or retarding the forming of the arcuateistep in the side of'the tubes. I 1 For a further exposition of my invention reference maybe' had to the annexed drawings and I specification at the end whereof my invention willlbe specifically pointed out'and claimed.

:Inxthe drawings, -.Fig.. 1 is a front or face tion of my device. Fig. 2 is a side view of the same modification. Fig. 3 is an end View of the samemodification. Fig.4 is a face or front view of the same modification showing the tube-cup and preformer.

view of one modifica- "JFig. 6 isan end view of the tubeshown in 4 fold 9. y the side in Fig. 2 forms a Gothic arc as it changes large as inch is permissible fora one inch Figure 8.

after it has been preformed but before it has been closed and folded.

Fig. 7 is a front or face view of another modiout into the cylindrical part of the tube with a convex taper-Sending at the end 6 of the straight The outline of the tube as seen from from the cylindrical portion H of the tube 1 into therelatively short, curved portion 8 at the fold 9, which fold may be of any type and may be either-plainorcorrugated. The arcuate step or Mob 1 formed between the sides of the cylindrical portion ll of the tube 1 and the ends 6 of the fold 9 is formed by the spreadingand bending of the walls of the tube during the closing or folding operations. The arcuate step or arch 1 has its intermediate part ll nearest fold 9 and has its end 18 curving away from fold 9 and is substantially smooth or regular.

. Figs; 4, and 6 show one process of closing the tube shown in Figs. 1,2 and 3. This process consists in placing the cylindrical tube I' in 'a'tubecup 26 having its upper end formed with arcuate or curved portions 2|. 1 A preformer consisting of. central preformer blades or spreaders 32 are adjustably secured to the preformer by means of bolts and nuts cooperating with slots. The preformer also carries on the outside of the spreaders 32 centralizing and equalizing wings 3I. The preformer spreads the top of the open end of tube I from a circular cross section into agenerally rectangular cross section as seen in Fig. 6.

The preformer then engages the top or'open end,

of the tube between the spreaders 32 and the wings 3 l and presses" the tube 1 down against the arcuate portions 2lof the tube-cup 26' thereby forming arcuate steps or arches 1 in'the walls of "thetube. The preformer is then removed from:

the tube and the tube-conveyed toanother station of the machine where the open end is closed and folded in any convenient manner, as for example that set forth in my'co-pendin'g application for 933, Serial to certain users. The top of the tube-cup does not I come quite as close to the top of the open end of the tube and the terminal point of the tube-cup is worked out to a different shape, having curves in both directions presenting a bow shape, so as to form a step 43 0f less pronounced depth. The

tube in being preformed by this new and novel method, while being supported in'a tube-cup, takes a distinctly square outline with sidesof convexo-concave outline in Fig.9. The cylindrical portion ll of tube- I draws in at 40 and corners 48 form, extending outside theperiphe ry of the cylindrical portion II as indicated clearly in drawn-in portion 40 and the flattened face and back of the tube. To prevent the forming of dents by the. natural tendency of the tube body'to expand-at-the corner-s48, thetube-cupin which these tubes areformed is relieved at the corners, -75

The corners 48 are formed by the the high point being in between these relieved points in the shorter dimension. It should be noted that, as the tube is preformed, it takes the shape of an are along its end, and the sides, in relationship to each other, also form into arcs when looking from the top of the tube in Figure 9. A definite relationship exists between the distance from the top of the tube-cup and the top or end of the open tube I, which if exceeded one way or another has a tendency to deform the tube and cause wrinkles or dents in various parts of the tube body. The relationship between the relieved portions and the high points or top of the tubecup is also definite for each size of tube.

A closed or finished tube is shown in Figs. 7 through 9 of this modified type. It should be noted that the convex taper 5| is somewhat longer in the modified tube, Figure 8, than in the previous one, Figure 2, and that the tube body I clearly tapers in at 40, Figure 7.

Any type of fold or number of folds may, of course, be used with this modified type of tube closure and these may either be plain or corrugated.

I do not intend to be limited in the practice of my invention save as the scope of the prior art and of the attached claims inay require.

I claim:

1. A process of forming a closure on collapsible tubes, which process consists in the steps of, spreading the sides of the open end of a tube of substantially circular cross section until said open end assumes a substantially rectangular cross section, forming arcuate steps or arches in the sides of said tube by partially supporting said tube adjacent said open end on arcuate or arch shaped means and compressing the open end of said tube against said means by applying pressure to said tube internally and externally of said open end, and closing and folding the open end of said tube.

2. A process of forming a closure on collapsible tubes, which process consists in the steps of, spreading the sides of the open end of a tube of substantially circular cross section until said open end assumes a substantially elongated cross section having the longer sides bowed outwardly from the axis of said tubein cross section and bowed with the highest part in the center of said tube in side elevation, forming arcuate steps or arches in the sides of said tube by partially supporting said tube adjacent said open end on arcuate or arch shaped means and compressing the open end of said tube against said means by applying pressure to said tube internally and externally of said open end, and closing and folding the open end of said tube.

CHARLES J. WESTIN. 

